Japan expects a sharp temperature drop starting Thursday, Nov. 21, followed by a rare heat wave beginning around Sunday, Nov. 24 [1, 2].
These extreme swings in temperature pose challenges for public health and energy demand as the country transitions from unseasonable warmth to sudden cold and back to intense heat.
Forecaster Sakaguchi Aimi of TBS NEWS DIG said that warm air flowed into the region from Monday, Nov. 18, to Wednesday, Nov. 20, causing temperatures to rise above average [1]. In Tokyo, the maximum temperature reached 29.3°C on Nov. 18 and climbed to 29.7°C on Nov. 20 [1]. Fukushima prefecture experienced even more extreme heat, with a maximum temperature of 35°C on Nov. 19 and 32.7°C on Nov. 20 [1].
This period of warmth will end abruptly. A cold front from the north is expected to bring rain and a significant temperature decline on Thursday, Nov. 21 [1, 2]. Tokyo's maximum temperature is forecast to drop to 22°C on that day [1]. In Fukushima, the maximum temperature is expected to plummet to 15°C [1].
The cooling trend will continue into the following days. Minimum temperatures for Nov. 22 and Nov. 23 are expected to reach 13°C in Tokyo and 9°C in Fukushima [1].
However, the volatility will not end with the cold front. Starting around Sunday, Nov. 24, Japan is expected to enter a period of unusually high heat that could last for about one week [1, 2]. This upcoming event has been described as a "once in 10 years" occurrence [2].
Caster Inoue Takahiro said he questioned the trajectory of the weather after the current warmth [1]. The shift from a cold front to an intense heat wave marks a period of extreme atmospheric instability for the region.
“Japan expects a sharp temperature drop starting Thursday, Nov. 21, followed by a rare heat wave.”
The rapid oscillation between extreme heat and sudden cold suggests a highly unstable atmospheric pattern. When temperatures swing by more than 10 degrees Celsius within a few days, it typically increases the risk of respiratory illnesses and puts sudden pressure on the power grid as residents pivot rapidly between heating and cooling systems.
